Carbonic nanostructures in subsurface rocks: problem review Part II. Graphene, carbonic nanotubes, nanofibers

Abstract

The paper reviews the publications on the search and exploration of carbonic nanotubes and other nanocarbonic structures in subsurface rocks. It is shown that the graphenes and carbonic nanotubes (CNT) exist in the composition of various magmatic and sedimentary rocks. They are formed in the graphite globules of volcanic rocks, as well as in the sediments, where the pressure, the particles of metallic catalysts, the tension stresses and time factors in million years compensate the absence of high temperatures. Experimental laboratory modeling of natural processes has been carried out and the reality of formation of carbonic nanostructures during the pyrolysis of volcanic gases on the lava catalysts, mechanical activation and processing of amorphous carbon or bituminous coal shown. Principal possibility of realization of technology of CNT mass production via pyrolysis of hydrocarbon crude material in the presence of different catalytically-active natural minerals has been reviewed and proven. The analysis of the aspects following the activity of mud volcanoes shows that there are all suppositions for the formation of carbonic nanostructures: the pressure bump of deep rocks out of the hot eruptive centre, methane as carbonic crude, catalytically-active breccias containing transition metals and their oxides, the process of methane burning in the medium poor of oxygen. However, it is not yet absolutely clear. As a working hypothesis we propose a model of formation of these structures due to the mud volcanism activity in the reactions of methane flow, the catalysts in which natural minerals exist. In such processes as a result of intensive methane flow, there occur negative pressure values and cavitation effects in the presence of which local temperature and pressure increase efficient for formation of adamantine and nanosize carbonic structures take place. In case if this mechanism is real, the studies point to a perspective of obtaining valuable products in conditions of natural geological processes. There are no messages or publications yet on the exploration of carbonic nanostructures in the rocks of mud volcanoes.